Multilayer-type on-chip inductor structure

Abstract

A multilayer-type on-chip inductor with a conductive structure includes an insulating redistribution layer disposed on an inter-metal dielectric (IMD) layer, and first and second winding portions symmetrically arranged in the IMD layer and the insulating redistribution layer with respect to a symmetrical axis. The first and second winding portions each includes at least first and second semi-circular stacking layers arranged from the inside to the outside and in concentricity. The first and second semi-circular stacking layers each has a first trace layer in the insulating redistribution layer and a second trace layer in the IMD layer and correspondingly formed below the first trace layer. A first slit opening passes through the second trace layer and extends in the extending direction of the length of the second trace layer.

What is claimed is: 
     
       1. A multilayer-type on-chip inductor structure, comprising:
 an insulating redistribution layer disposed on an inter-metal dielectric layer; and 
 first and second winding portions symmetrically arranged in the inter-metal dielectric layer and the insulating redistribution layer with respect to a symmetrical axis, the first and second winding portions each comprising at least first and second semi-circular stacking layers arranged from the inside to the outside and in concentricity, and first and second semi-circular stacking layers each comprising: 
 a first trace layer disposed in the insulating redistribution layer; and 
 a second trace layer disposed in the inter-metal dielectric layer and correspondingly formed below the first trace layer, wherein a first slit opening is formed in and passes through the second trace layer and extends along a length of the second trace layer, 
 wherein there is an equal number of trace layers in the first semi-circular stacking layer as in the second semi-circular stacking layer. 
 
     
     
       2. The structure as claimed in  claim 1 , wherein the first and second semi-circular stacking layers each further comprises:
 a plurality of conductive plugs disposed between the first trace layer and the second trace layer, so that the first trace layer is electrically connected to the second trace layer. 
 
     
     
       3. The structure as claimed in  claim 1 , further comprising:
 a connecting layer pair disposed between the first winding portion and the second winding portion, comprising: 
 an upper cross-connection layer connecting the first trace layer of the second semi-circular stacking layer of the first winding portion to the first trace layer of the first semi-circular stacking layer of the first winding portion; and 
 a lower cross-connection layer connecting the second trace layer of the first semi-circular stacking layer of the first winding portion to the second trace layer of the second semi-circular stacking layer of the second winding portion, wherein a second slit opening passes through the lower cross-connection layer and extends in an extending direction of a length of the lower cross-connection layer. 
 
     
     
       4. The structure as claimed in  claim 3 , wherein the second slit opening is connected to the first slit opening in the second trace layer of the first semi-circular stacking layer of the first winding portion and the first slit opening in the second trace layer of the second semi-circular stacking layer of the second winding. 
     
     
       5. The structure as claimed in  claim 3 , further comprising a third slit opening passing through the second trace layer and extending in an extending direction of a length of the first slit opening. 
     
     
       6. The structure as claimed in  claim 5 , further comprising a fourth slit opening passing through the lower cross-connection layer and extending in an extending direction of a length of the second slit opening. 
     
     
       7. The structure as claimed in  claim 6 , wherein the fourth slit opening is connected to the third slit opening in the second trace layer of the first semi-circular stacking layer of the first winding portion and the third slit opening in the second trace layer of the second semi-circular stacking layer of the second winding portion. 
     
     
       8. The structure as claimed in  claim 1 , wherein two ends of the second trace layer of the second semi-circular stacking layer of the first winding portion are spaced apart from two corresponding ends of the first slit opening by a distance. 
     
     
       9. The structure as claimed in  claim 1 , wherein an end of the second trace layer of the second semi-circular stacking layer of the second winding portion is spaced apart from a corresponding end of the first slit opening formed therein by a distance, and wherein an end of the second trace layer of the first semi-circular stacking layer of the second winding portion is spaced apart from a corresponding end of the first slit opening by a distance. 
     
     
       10. The structure as claimed in  claim 1 , wherein the first trace layer and the second trace layer each has an inner edge and an outer edge, and wherein the inner edge of the first trace layer is substantially aligned to the inner edge of the second trace layer, and the outer edge of the first trace layer is substantially aligned to the outer edge of the second trace layer. 
     
     
       11. The structure as claimed in  claim 1 , wherein the thickness of the first trace layer is greater than the thickness of the second trace layer. 
     
     
       12. A multilayer-type on-chip inductor structure, comprising:
 an insulating redistribution layer disposed on an inter-metal dielectric layer; and 
 first and second winding portions symmetrically arranged in the inter-metal dielectric layer and the insulating redistribution layer with respect to a symmetrical axis, first and second winding portions each comprising at least first and second semi-circular stacking layers arranged from the inside to the outside and in concentricity, and first and second semi-circular stacking layers each comprising: 
 a first trace layer disposed in the insulating redistribution layer; 
 a second trace layer disposed in the inter-metal dielectric layer and correspondingly formed below the first trace layer, wherein a first slit opening is formed in and passes through the second trace layer and extends along a length of the second trace layer; and 
 a third trace layer disposed in the inter-metal dielectric layer and correspondingly formed below the second trace layer, wherein a second slit opening is formed in and passes through the third trace layer and is correspondingly formed below the first slit opening, 
 wherein there is an equal number of trace layers in the first semi-circular stacking layer as in the second semi-circular stacking layer. 
 
     
     
       13. The structure as claimed in  claim 12 , wherein the first and second semi-circular stacking layers each further comprises:
 a plurality of first conductive plugs disposed between the first trace layer and the second trace layer, so that the first trace layer is electrically connected to the second trace layer; and 
 a plurality of second conductive plugs disposed between the second trace layer and the third trace layer, so that the second trace layer is electrically connected to the third trace layer. 
 
     
     
       14. The structure as claimed in  claim 12 , wherein the first trace layer, the second trace layer, and the third trace layer each has an inner edge and an outer edge, and wherein the inner edge of the first trace layer is substantially aligned to the inner edge of the second trace layer and the inner edge of the third trace layer, and the outer edge of the first trace layer is substantially aligned to the outer edge of the second trace layer and the outer edge of the third trace layer. 
     
     
       15. The structure as claimed in  claim 12 , wherein the thickness of the first trace layer is greater than the thickness of the second trace layer. 
     
     
       16. A multilayer-type on-chip inductor structure, comprising:
 an insulating redistribution layer disposed on an inter-metal dielectric layer; and 
 first and second winding portions symmetrically arranged in the inter-metal dielectric layer and the insulating redistribution layer with respect to a symmetrical axis, first and second winding portions each comprising at least first and second semi-circular stacking layers arranged from the inside to the outside and in concentricity, and first and second semi-circular stacking layers each comprising: 
 a first trace layer disposed in the insulating redistribution layer; 
 a second trace layer disposed in the inter-metal dielectric layer and correspondingly formed below the first trace layer, wherein a first slit opening is formed in and passes through the second trace layer and extends along a length of the second trace layer; and 
 a third trace layer disposed in the inter-metal dielectric layer and correspondingly formed below the second trace layer, wherein a second slit opening is formed in and passes through the third trace layer and is correspondingly formed below the first slit opening, and wherein a third slit opening and a fourth slit opening are formed in and pass through the third trace layer and extend along a length of the second slit opening. 
 
     
     
       17. The structure as claimed in  claim 16 , wherein the first and second semi-circular stacking layers each further comprises:
 a plurality of first conductive plugs disposed between the first trace layer and the second trace layer, so that the first trace layer is electrically connected to the second trace layer; and 
 a plurality of second conductive plugs disposed between the second trace layer and the third trace layer, so that the second trace layer is electrically connected to the third trace layer. 
 
     
     
       18. The structure as claimed in  claim 16 , wherein the second slit opening is disposed between the third slit opening and the fourth slit opening. 
     
     
       19. The structure as claimed in  claim 16 , wherein the first trace layer, the second trace layer, and the third trace layer each has an inner edge and an outer edge, and wherein the inner edge of the first trace layer is substantially aligned to the inner edge of the second trace layer and the inner edge of the third trace layer, and the outer edge of the first trace layer is substantially aligned to the outer edge of the second trace layer and the outer edge of the third trace layer. 
     
     
       20. The structure as claimed in  claim 16 , wherein the thickness of the first trace layer is greater than the thickness of the second trace layer.